The invention relates to a twin-disc clutch, particularly for a motor vehicle.
Already known from DE-A-No. 3 041 342 is a twin-disc clutch having a flywheel rotatable about an axis of rotation and on which there is mounted a clutch housing composed of two axially adjacently disposed housing parts. A pressure plate is axially movably but non-rotatably guided on the housing part which is axially remote from the flywheel. Between the flywheel and the pressure plate, there is an intermediate plate which is non-rotatably but axially movably guided on the other housing part. Between the intermediate plate and the flywheel which forms a counter pressure plate there is a first clutch friction disc while a second clutch friction disc is disposed between the intermediate plate and the pressure plate. The pressure plate is tensioned against the flywheel by a main clutch spring, in this case a diaphragm spring, via the two clutch friction discs and the intermediate plate. When de-clutching, in order to ensure that the intermediate plate is lifted off the first clutch friction disc, an easing-spring means is provided which tensions the intermediate plate away from the flywheel. The easing-spring arrangement comprises pre-tensioned tangential leaf spring which also take over the non-rotatable but axially movable guidance of the intermediate plate.
It is intended that the intermediate plate perform only half the travel of the pressure plate, to ensure that both clutch friction discs are disengaged when de-clutching. Where the known twin-disc clutch is concerned, the pressure plate is connected to the housing via a plurality of articulated levers. The levers have in each case one end connected by a first joint to the pressure plate while their other end is connected to the housing by a second joint. The intermediate plate carries, associated with the levers, projections which bear on the middle of the levers, the pressure plate controlling the movement of the intermediate plate during de-clutching. To facilitate assembly of the twin-disc clutch, the joint mounting the lever on the housing is connected to the housing via an adjusting means. Once a friction force has been overcome, the adjusting means permits of axial displacement of the second articulation. Certainly, it has become manifest that this type of adjusting means must be dimensioned for relatively low displacement forces by virtue of the lever action of the lever. However, such relatively low displacement forces result in tolerance problems in series production.
Known from U.S. Pat. No. 4,257,502 is a further twin-disc clutch in which the lift-off movement of the intermediate plate is controlled by levers which are mounted at both ends on journal bearings of the pressure plate on the one hand and the housing on the other. The levers are fitted radially on the journal bearings and are held on the intermediate plate by a screw which passes through an elongated hole in the middle of the lever. A spring-loaded friction device adjusts the location of the lever relative to the intermediate plate. Where assembly of the prior art twin-disc clutch is concerned, the levers must be installed after assembly of the two housing parts which guide the pressure plate and the intermediate plate. Thus, assembly of the twin-disc clutch is comparatively time-consuming.
The invention is directed towards indicating a twin-disc clutch in which the elements which provide for controlled lift-off of the intermediate plate are non-problematical in respect of any tolerances, and which can be assembled at relatively low cost.